Method and device for creating frozen pellets of a foodstuff

ABSTRACT

In one embodiment, a method of forming frozen ice cream pellets includes supplying an ice cream premix into a loading vessel; loading a loading cylinder with the ice cream premix from the loading vessel, the loading cylinder being connected to the loading vessel; applying a machine-controllable force to expel the ice cream premix from the loading cylinder as ice cream premix pellets; and exposing the ice cream premix pellets to a cryogenic fluid, thereby at least partially freezing the ice cream premix pellets.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/681,084, filed Mar. 1, 2007, which claims the benefit under 35 U.S.C.§119(e) to U.S. Provisional Application No. 60/809,902, filed May 31,2006 and to U.S. Provisional Application No. 60/810,321, filed Jun. 2,2006. The entire contents of each aforementioned application areincorporated herein by reference.

BACKGROUND

Sales of frozen foodstuff have risen dramatically in recent years. Inparticular, ice cream and yogurt product in the form of pellets havebecome very popular.

One method of forming the pellets involves delivering flavored liquiddairy composition to a feed tray and then dripping the composition intoa freezing chamber. The feed tray includes a sieve plate having orificesformed therein. The liquid dairy composition passes through the sieveplate and forms pellets that fall into the freezing chamber. The fallingpellets of liquid compositions freeze rapidly in the freezing chamber,thereby forming solid pellets of flavored ice cream or yogurt product.The frozen pellets are removed from the freezing chamber and packed fordistribution and later consumption.

One problem encountered with the drip system is the production ofpellets having different sizes. The non-uniform sized pellets detractfrom the appearance of the product. Additionally, the drip system alsocauses the pellets to drip at different times, thereby causing poor“belt loading.” Poor belt loading occurs when an insufficient quantityof pellets land in the cooling medium at any one time.

Poor belt loading results in an inefficient use of the cooling medium,because more cooling medium will be required to freeze the same quantityof pellets.

There is, therefore, a need for methods and apparatus for the productionof pellets for frozen foodstuff. There is also a need for methods andapparatus for producing frozen food pellets of uniform size.

SUMMARY

Embodiments of the present invention relate to methods and apparatus forproducing frozen pellets of a foodstuff, in particular, pellets of anice cream premix. In one embodiment, an injector apparatus is adapted torelease pellets of the ice cream premix into a cooling medium.

In one embodiment, a method of forming a frozen foodstuff pelletincludes supplying a foodstuff premix into a loading vessel; loading aloading cylinder with the foodstuff premix from the loading vessel, theloading cylinder being connected to the loading vessel; applying a forceto expel the foodstuff premix from the loading cylinder; and exposingthe foodstuff premix to a cryogenic fluid, thereby at least partiallyfreezing the foodstuff premix.

In another embodiment, a method of forming frozen ice cream pelletsincludes supplying an ice cream premix into a loading vessel; loading aloading cylinder with the ice cream premix from the loading vessel, theloading cylinder being connected to the loading vessel; applying amachine-controllable force to expel the ice cream premix from theloading cylinder as ice cream premix pellets; and exposing the ice creampremix pellets to a cryogenic fluid, thereby at least partially freezingthe ice cream premix pellets. In another embodiment, applying themachine-controllable force comprises injecting pressurized air into theloading vessel. In yet another embodiment, applying themachine-controllable force comprises injecting ice cream premix underpressure into the loading vessel.

In another embodiment, a method of forming frozen ice cream pelletsincludes operating a reciprocating piston to supply ice cream premixinto a loading vessel; depositing the ice cream premix from the loadingvessel into a transport apparatus containing a cooling medium; and atleast partially freezing the ice cream premix into pellets whiletransporting the ice cream away from the loading vessel.

In yet another embodiment, an apparatus for forming frozen ice creampellets includes an injector apparatus for depositing ice cream pelletsand a cooling medium for at least partially freezing the ice creampellets. In one embodiment, the injector apparatus may include a loadingvessel and a reciprocating piston apparatus for supplying ice creampremix to the loading vessel. In another embodiment, the injectorapparatus may include a loading vessel; a loading cylinder connected toa lower portion of the loading vessel and configured to deposit the icecream pellets; and a pressurized source connected to the loading vesselfor supplying fluid pressure to the loading vessel.

BRIEF DESCRIPTION OF THE DRAWINGS

For a further understanding of the nature and objects of the presentinvention, reference should be made to the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich like elements are given the same or analogous reference numbersand wherein:

FIG. 1 illustrates an embodiment of a pelletizer assembly for producingfrozen pellets of foodstuff;

FIG. 2 illustrates another embodiment of a pelletizer assembly;

FIG. 3 illustrates another embodiment of a pelletizer assembly;

FIG. 4 illustrates an embodiment of an injector apparatus for use with apelletizer assembly;

FIG. 4A illustrates an exploded view of a loading cylinder;

FIG. 5 illustrates another embodiment of a pelletizer assembly;

FIG. 6 illustrates another embodiment of a pelletizer assembly; and

FIG. 7 illustrates an embodiment of a pump controlled depositingapparatus.

DESCRIPTION OF PREFERRED EMBODIMENTS

Embodiments of the present invention relate to methods and apparatus forproducing frozen pellets of a foodstuff, in particular, pellets of anice cream premix. In one embodiment, an injector apparatus is adapted torelease pellets of the ice cream premix into a cooling medium.

FIG. 1 shows a pelletizer assembly 100 according to one embodiment ofthe present invention. The assembly 100 includes a storage tank 110 fora cooling medium 117, preferably liquid nitrogen, and a pump 115 forpumping the cooling medium 117 to a trough 125. The trough 125 may behorizontally positioned at a downward angle such that the cooling medium117 may flow down toward a conveyor belt 135. An outlet of an injectorapparatus 130 is located above the upper end of the trough 125 fordelivering foodstuff pellets 132 into the trough 125 and the coolingmedium 117. The length of the trough 125 is dimensioned such thatsufficient time is provided for the cooling medium 117 to at leastfreeze the outer surface of the pellets 132. Thus, the core of thepellets 132 may still be liquid when the pellets 132 reach the end ofthe trough 125. The conveyor belt 135 is located below the trough 125 tocollect the at least partially frozen pellets 132. The conveyor belt 135is adapted to collect the pellets 132 on the conveyor belt 135 but allowthe cooling medium 117 to pass through. An exemplary material for theconveyor belt 135 is a metal screen. The cooling medium 117 is collectedby a fluid collection apparatus 119 and returned to the storage tank110. In another embodiment, the length of the trough 125 may be selectedto ensure that the pellets 132 are completely frozen by the time thepellets 132 reach the end of the trough 125. In another embodiment, thecooling medium may be any suitable cryogenic fluid known to a person ofordinary skill in the art.

The pellet freezing process in the trough 125 vaporizes some of thecooling medium 117 to produce a vaporized cooling medium 118. The trough125 and the conveyor belt 135 may be encased by a heat-insulating casing140 in such a way that the vaporized cooling medium 118 are drawn offabove the conveyor belt 135 in parallel flow with the transportdirection of the pellets 132. In one embodiment, the vaporized coolingmedium 118 is drawn off by an exhaust-gas fan 145 installed above theend of the conveyor belt 135. In this respect, the direction of flow ofthe gaseous cooling medium 118 corresponds to the transport direction ofthe pellets 132 on the conveyor belt 135. Thus, the flow of gaseouscooling medium 118 may continue to remove energy from the pellets 132during transport on the conveyor belt 135. The length and speed of theconveyor belt 135 and the flow conditions of the vaporized coolingmedium 118 may be selected in such a way that the pellets 132 arecompletely frozen by the time it reaches the end of the conveyor belt135. The frozen pellets 132 are collected in the container 150.

In another embodiment, the conveyor belt 135 may be arranged in linewith, in the opposite direction of, or crosswise the direction of thetrough 125. In one arrangement, the trough 125 may be divided into aplurality of shorter troughs 225 on which the cooling medium flow andpellets 232 may flow forwards and backwards, as shown in FIG. 2. Thedivided trough 225 is beneficial for a space-saving type ofconstruction. In a crosswise arrangement, a plurality of troughs 225 mayfeed directly to one conveyor belt 235 as illustrated in FIG. 3.

FIG. 4 shows an embodiment of an injector apparatus 130 suitable for usewith the pelletizer assembly 100. The injector apparatus 130 includes aloading vessel 410 having a bottom wall with multiple holes 415 in fluidcommunication with a respective loading cylinder 420. In the embodimentshown in FIG. 4, the injector apparatus 130 includes a large rectangularloading vessel 410 having dimensions of at least about 30″ L×6″ W×18″ H.The bottom wall of the loading vessel 410 has multiple, uniformlyaligned holes 415 that are positioned as closely as possible inproximity to each other. In one embodiment, each hole 415 isapproximately 0.5″ in diameter. It must be noted that the holes 415 maybe positioned in any suitable manner, for example, evenly spaced apart,random, aligned diagonally, vertically, or horizontally, or combinationsthereof.

Each hole 415 may be fitted with a small diameter loading cylinder 420.In one embodiment, the loading cylinders 420 are positioned above anopening in the pelletizer 100 such that the pellets 132 expelled fromthe loading cylinders 420 may land in the cooling medium 117 flowing inthe trough 125. Referring to FIG. 4A, the loading cylinder 420 may havean enlarged, beveled opening at the top to facilitate connection to therespective hole 415 in the loading vessel 410. Exemplary forms of theloading cylinder 420 include a short nozzle, a long tube, or any formsuitable for delivering the pellets 132. The diameter of the loadingcylinder 420 may be sized to prevent the ice cream premix to drip fromthe loading cylinder 420 due to gravity alone. In one embodiment, theloading cylinder 420 is sized between about 2-5 mm ID and about 50-150mm long. In another embodiment, the loading cylinder 420 may be sizedbetween about 1-10 mm ID and about 10-250 mm long. A stabilizing supportplate 430 may be connected to the lower end of the cylinders 420 tostabilize and maintain the alignment of the loading cylinders 420 withrespect to the loading vessel 410.

A hole 433 may be provided at the top of the loading vessel 410 to allowice cream premix to be pumped into the loading vessel 410. A loadingtube 435 may be connected to the hole 433 to supply the ice cream premixto the loading vessel 410. In one embodiment, the tube 435 supplies theice cream premix in an airtight manner. A check valve 437 (or otherforms of one way valve) may be installed on the loading tube 435 toprevent the ice cream premix to flow backwards. The ice cream premix maybe pumped from flavor tanks or other premix storage vessels into therectangular loading vessel 410. In one embodiment, the ice cream premixis maintained at a level between about 15% to 95%; preferably, about 50%to 80%, of the loading vessel 410. In another embodiment, the ice creampremix is maintained at a level sufficient to maintain a proper headpressure above the loading cylinder 420 such that the desired size ofpellets 132 is ejected.

High pressure air, nitrogen, carbon dioxide vapor, or other compressedgas may be supplied into the headspace above the ice cream premix in theloading vessel 410. As shown in FIG. 4, a compressed gas line 440 isconnected to the loading cylinder 410 to supply gas as needed. The flowof compressed gas may be controlled through the use of a timer-operatedon/off solenoid valve 447.

In operation, the ice cream premix is supplied into the loading vessel410 using the loading tube 435. The premix may flow into the top portionof each loading cylinder 420 and may partially flow down the loadingcylinder 420. The viscosity of the premix, coupled with the length andthe restricted inner diameter of the cylinder 420, may restrict theability of the premix to flow smoothly through the cylinder 420, therebyblocking the cylinder 420 with the liquid premix. At this point, eachcylinder 420 is considered “loaded”. The premix may continue to besupplied until a predetermined level of premix in the loading vessel 410is reached.

The compressed gas may then be injected into the empty headspace of theloading vessel 410. The increase in pressure in vessel 410 forces someof the premix down and out of the cylinder 420, thereby depositing avolume of premix pellets 132 into the liquid nitrogen stream 117 andtrough 125 below. The desired size of premix pellets 132 to be depositedmay be controlled by managing the quantity of compressed air injectedinto the loading vessel 410. The next batch of pellets 132 may bedeposited as soon as the previous batch clears the path of the loadingcylinders 420. In this manner, the pellets 132 may be deposited into theliquid nitrogen 117 in the same accurate pattern and volume with eachactuation of the compressed gas.

The continuous stream of liquid nitrogen 117 carries away the depositedpremix pellets 132. The liquid nitrogen 117 at least partially freezesthe pellets 132. The trough 125 delivers the pellets 132 and the liquidnitrogen 117 to the conveyor belt 135, where the separated pellets areretained, while the liquid nitrogen 117 is recycled back to the storagetank 110. On the conveyor belt 135, the pellets 132 continue to solidifyuntil it is completely frozen. At the end of the conveyor belt 135, thefrozen pellets 132 are collected in the container 150. In this manner,an almost seamless, continuous flow of ice cream premix pellets 132 maybe applied in a very tight pattern without danger of excessive mating orfreezing together.

In another embodiment, the injector apparatus 130 may positioned on aload cell 460 or other suitable load measuring device, as shown inFIG. 1. The load cell 460 may be adapted to measure the load on theinjector apparatus 130 which is correlated to the level of premix in theloading vessel 410. As the premix is forced out of the rectangularloading vessel 410, the load cells 460 supporting the loading vessel 410may monitor volume of premix remaining in the loading vessel 410. Whenthe level of the premix reaches a preset lower limit, the premix pumpmay be activated to load premix into the loading vessel 410 through theloading tube 435. The premix loading may continue until the load cells460 register a preset upper limit. This cycle may be repeated tomaintain the premix volume in a steady range. The steady premix rangeprovides a constant head pressure on the loading cylinders 120, therebyassuring accurate deposition of the pellets 132. In another embodiment,the injector apparatus may be equipped with a sensor to measure theheight of the premix in the loading vessel 410. The quantity of premixmay be controlled based on the level of the premix measured by thesensor.

Advantages of one embodiment of this system include dramaticallyimproved coverage of ice cream premix pellets in the liquid nitrogen,substantially increased production rates, highly consistent pellet size,ability to vary pellet size through pressure, duration of compressed gascycle, and reduced incidence of product mating.

FIG. 5 illustrates a side view of another embodiment of a pelletizerassembly 300. As shown, the trough 325 is provided with a barrier 350disposed at the downstream end and an opening 355 for the pellets 332 toleave the trough 325. In one embodiment, the barrier 350 is configuredto retain the pellets 332, but allow the cooling medium 317 to pass.Exemplary barriers include a metal or non-metal structure having aplurality of apertures or perforations such as a metal screen, amultilayer screen, and any other suitable porous structure. The opening355 may be a slot or other apertures formed on the trough 325 and/orbetween the trough 325 and the barrier 350 and sufficiently sized forthe pellets 332 to pass. In use, the injector apparatus 330 deposits thepellets 332 in the trough 325, where they are cooled by the coolingmedium 317. The cooling medium 317 carries the pellets 332 toward theend of the trough 325 where the pellets 332 fall through the opening 355and land on the conveyor belt 335 or other collection apparatus. Thebarrier 350 retains the pellets 332 in the trough 325 until they fallthrough the opening 355. A portion of the cooling medium 317 passesthrough the opening 355 along with the pellets 332, while the remainingportion continues through the barrier 350 and falls on the conveyor belt335 at a point downstream of the opening 355. In this respect, thecooling medium 317 cascades on top of the pellets 332 that haveaccumulated on the conveyor belt 335. As a result, the at leastpartially frozen pellets 332 may receive another exposure to the coolingmedium 317 while being carried by the conveyor belt 335 toward thecollection container 150. The additional exposure of the pellets 332 tothe cooling medium 317 effectively increases the freezing capacity ofthe assembly 300. In another embodiment, the barrier 350 may be a solidwall such that all of the cooling medium 317 and pellets 332 are forcedthrough the opening 355.

FIG. 6 illustrates a top view of another embodiment of a pelletizerassembly 300. The pelletizer assembly 300 includes a trough 325 having apellet barrier 350. As shown, the end of the trough 325 is angledrelative to the direction of travel of the pellets 332. In oneembodiment, the end of the trough 325 is angled between about 30 degreesand 60 degrees, more preferably, between about 40 degrees and 50degrees. The conveyor belt 335 is positioned at about a right anglerelative to the trough 325 to collect the pellets 332 exiting theopening 355. However, it is contemplated that the trough end may haveany suitable angle, and the conveyor belt may be positioned at any anglecapable of collecting the pellets. In use, the injector apparatus 330deposits the pellets 332 in the trough 325, where they are cooled andcarried away by the cooling medium 317. At the end of the trough 325,the pellets 332 drop through the opening 355 and land on the conveyorbelt 335 or other collection apparatus. The barrier 350 stops thepellets 332 in the trough 325 until they fall through the opening 355.The angled end of the trough 325 allows the pellets 332 that fallthrough the opening 355 to spread across the width of the conveyor belt335. Some of the cooling medium 317 flows through the barrier 350 anddrenches the pellets 332 accumulated on the conveyor belt 335. As aresult, the at least partially frozen pellets 332 may receive anotherexposure to the cooling medium 317 while being carried by the conveyorbelt 335 toward the collection container 150.

In another embodiment, the injector apparatus 130 may utilize a pumpcontrolled depositing apparatus 535 to deposit the pellets 132 into theliquid nitrogen 117. In FIG. 7, the injector apparatus 130 in shown witha pump controlled depositing apparatus 535 for delivering ice creampremix to the loading vessel 410 and depositing pellets 132 into theliquid nitrogen 117. As shown, the depositing apparatus 535 has an inletend 510 connected to the premix source 505 and an outlet end 520connected to the loading vessel 410. A one way valve 512 is positionedat each end to control the flow of the premix. A loading chamber 530 isformed between the two valves 512, 522. The inlet valve 512 at the inletend 510 allows premix to enter the loading chamber 530, but not leave.The outlet valve 522 at the outlet end 520 allows the premix to leavethe loading chamber 530, but not enter. In one embodiment, each valve512, 522 is a ball valve having a ball biased by a biasing member suchas a spring. It is contemplated that other suitable one way valves maybe used.

The reciprocating piston pump apparatus 535 is used to draw the premixinto the loading chamber 530 and force the premix into the loadingvessel 410. In one embodiment, the piston pump 535 includes a fluidoperated reciprocating piston 550 cooperating with a fluid cylinder 540.The piston 550 includes a head 551 that forms a wall of the loadingchamber 530, whereby reciprocation of the head 551 changes the volume ofthe loading chamber 530. The piston 550 also includes a tail 552 locatedin the fluid cylinder 540. The injection of fluid in front of or behindthe tail 552 causes the axial of the movement of the piston 551. Fluidmay injected into the fluid cylinder 552 via one of two fluid ports 541,542 located at each end of the cylinder 540. In another embodiment,piston may be reciprocated by an electric motor.

In operation, the loading vessel 410 is initially full charged with theice cream premix. Pressurized gas is supplied through the first port 541in front of the tail 552 to cause the piston to move to the left,thereby increasing the volume of the loading chamber 530. The loadingchamber expansion causes the ice cream premix to be drawn through theinlet valve 512 to fill the loading chamber 530. The ice cream premix inthe loading vessel 410 cannot come back through the outlet valve 522 dueto the one-way nature of the valve 522. Thereafter, pressurized gas issupplied through the second port 542 behind the tail 552 of the piston550 to cause the piston 550 to move toward the loading chamber 530,thereby decreasing the volume of the loading chamber 530. This reductionin volume forces the premix to exit the loading chamber 530 through theoutlet valve 522. The ice cream premix is not forced back into thepremix source 505 due to the one way nature of the inlet valve 512.Because the loading vessel 410 was fully charged, the newly injectedpremix displaces premix pellets 132 out from the bottom of the loadingcylinder 420 and into the liquid nitrogen. The cycle may be repeated todeposit more ice cream premix pellets into the liquid nitrogen.

It will be understood that many additional changes in the details,materials, steps, and arrangement of parts, which have been hereindescribed and illustrated in order to explain the nature of theinvention, may be made by those skilled in the art within the principleand scope of the invention as expressed in the appended claims. Thus,the present invention is not intended to be limited to the specificembodiments in the examples given above and/or the attached drawings.

What is claimed is:
 1. An apparatus for forming frozen ice creampellets, comprising: an injector apparatus for depositing ice creampellets, the injector apparatus including; a loading vessel; and areciprocating piston apparatus for supplying ice cream premix to theloading vessel; and a cooling medium positioned to receive the ice creampellets deposited by the injector apparatus, the cooling medium capableof at least partially freezing the ice cream pellets.
 2. The apparatusof claim 1, further comprising a loading cylinder connected to a lowerportion of the loading vessel and configured to deposit the ice creampellets in response to a force applied by the reciprocating pistonapparatus.
 3. The apparatus of claim 1, wherein the reciprocating pistonapparatus comprises a piston and a loading chamber defining a chambersized to allow the piston to travel therethrough, wherein reciprocationof the piston changes a volume of the chamber.
 4. The apparatus of claim1, further comprising a conveyor belt for transporting the ice creampellets.
 5. An apparatus for forming frozen ice cream pellets,comprising: an injector apparatus for depositing ice cream pellets, theinjector apparatus including; a loading vessel; a loading cylinderconnected to a lower portion of the loading vessel and configured todeposit the ice cream pellets; and a pressurized source connected to theloading vessel for supplying fluid pressure to the loading vessel; and acooling medium positioned to receive the ice cream pellets deposited bythe injector apparatus, the cooling medium capable of at least partiallyfreezing the ice cream pellets.
 6. The apparatus of claim 5, furthercomprising a conveyor belt for transporting the ice cream pellets.